WO2014132415A1

WO2014132415A1 - Fluorescence and phosphorescence detecting method and device, and valuable media authenticity determining method and device

Info

Publication number: WO2014132415A1
Application number: PCT/JP2013/055553
Authority: WO
Inventors: 佐藤　剛; 博小西; 史哲嶋岡
Original assignee: グローリー株式会社
Priority date: 2013-02-28
Filing date: 2013-02-28
Publication date: 2014-09-04

Abstract

A fluorescence and phosphorescence detecting method for detecting fluorescent emission and phosphorescent emission which have different light emission intensity time characteristics when exposed to the same excitation light comprises: a first excitation light exposure step of emitting excitation light, at a first emission intensity, toward a valuable media during a first exposure time; a first emission light volume measurement step of measuring the amount of emission light from the valuable media that is excited by way of the excitation light emitted in the first excitation light exposure step; a second excitation light exposure step of emitting excitation light, at a second emission intensity that is set so that the light volume is the same as the excitation light emitted in the first excitation light exposure step, toward a valuable media during a second exposure time that is different than the duration of the first exposure time; a second emission light volume measurement step of measuring the amount of emission light from the valuable media that is excited by way of the excitation light emitted in the second excitation light exposure step; and a determination step of determining whether the light emission from the valuable media is fluorescent emission or phosphorescent emission by comparing the measurement result obtained with the first emission light volume measurement step to the measurement result obtained with the second emission light volume measurement step.

Description

Fluorescence / phosphorescence detection method and apparatus, and valuable medium authenticity determination method and apparatus

The present invention provides a fluorescence / phosphorescence detection method and apparatus for detecting fluorescence emission and phosphorescence emission observed in a valuable medium, and a truth for determining the authenticity of a valuable medium using the fluorescence / phosphorescence detection method. The present invention relates to a false determination method and apparatus.

In recent years, various types of ink have been used for valuable media such as banknotes and checks. For example, there are inks in which fluorescence emission is observed by irradiating excitation light of a predetermined wavelength and inks in which phosphorescence emission is observed. If a mark or the like is printed on the valuable medium using such ink, the authenticity of the valuable medium can be determined from the relationship between the irradiation timing of the excitation light and the emission state of the excited light emission.

For example, Patent Document 1 discloses a technique for detecting both fluorescence emission and phosphorescence emission. This apparatus distinguishes and detects fluorescence and phosphorescence from the relationship between the irradiation timing of excitation light and the timing at which the excited light is measured. Specifically, while conveying paper sheets, ultraviolet light, which is excitation light, is irradiated at a predetermined position, and fluorescence emission excited by the paper sheets is measured by a sensor provided at this position. Then, at a position downstream of the conveyance direction from the position where the fluorescence emission is measured, another sensor provided at this position measures the phosphorescence emission observed without being irradiated with the excitation light after the excitation light irradiation. To do.

Also in Patent Document 2, fluorescence and phosphorescence are measured in a bright phase in which excitation light is irradiated on a measurement target, and phosphorescence is measured in a dark phase in which excitation light is not irradiated after excitation light irradiation. And a technique for detecting both phosphorescence is disclosed.

Patent Document 3 discloses a technique for measuring the emission intensity of each of fluorescence and phosphorescence using a filter from a measurement object in which both fluorescence emission and phosphorescence emission are observed. Specifically, when measuring in the bright phase and the dark phase using two sensors, one sensor uses a filter to measure only fluorescence emitted in a predetermined wavelength range, and the other sensor Measure light in the entire wavelength range including fluorescence and phosphorescence. Then, phosphorescence is detected from the difference between the measurement result of light in the entire wavelength region and the measurement result of fluorescence.

Further, Patent Document 4 discloses a technique for detecting phosphorescence emission based on a temporal change in emission intensity of phosphorescence emission. Specifically, fluorescence emission shows a substantially constant emission intensity immediately after excitation light irradiation until excitation light irradiation stops, whereas phosphorescence emits excitation light after starting excitation light irradiation. The emission intensity gradually increases until it stops. Using this characteristic at the time of phosphorescence emission, based on the integral value within a predetermined time after the excitation light irradiation of the signal whose emission intensity was measured, and the integral value within a predetermined time immediately before stopping the excitation light irradiation, It detects phosphorescence.

JP 2010-60524 A International Publication No. 2010/018353 JP-T-2001-506001 Japanese Patent No. 4048121

However, according to the above prior art, fluorescence and phosphorescence may not be detected accurately. For example, in the technique described in Patent Literature 1, two sensors provided at different positions are used to detect fluorescence and phosphorescence at one sensor position, and then a sheet is further conveyed to the other sensor. Detect phosphorescence at the position. For this reason, there is a possibility that a measurement error may occur due to the influence of the positional deviation or fluttering of the paper sheets generated during the conveyance between the sensors.

In the techniques described in Patent Document 2 and Patent Document 3, measurement by the same sensor can be performed, but it is necessary to use the measurement result in the dark phase. Phosphorescence emission in the dark phase has a small emission intensity and may be affected by noise, resulting in a measurement error.

In the technique described in Patent Document 4, since the signal used for phosphorescence detection is a short-time signal, it may be affected by noise. For example, Patent Document 4 discloses that the integral value is obtained with a time length of 25% or less of the time from when the excitation light irradiation is started to when it is stopped. With this time length, phosphorescence is emitted. The intensity is low, and measurement errors may occur due to the influence of noise.

The present invention has been made to solve the above-described problems caused by the prior art, and can accurately distinguish and detect the fluorescence emission and phosphorescence emission observed in a valuable medium, and can distinguish the type of phosphorescence. It is an object of the present invention to provide a fluorescence / phosphorescence detection method and apparatus, and a true / false determination method and apparatus for determining the authenticity of a valuable medium using the fluorescence / phosphorescence detection method.

In order to solve the above-described problems and achieve the object, the present invention is a fluorescence / phosphorescence detection method for detecting fluorescence emission and phosphorescence emission having different time characteristics of emission intensity when irradiated with the same excitation light. The first excitation light irradiation step of irradiating the valuable medium with the excitation light for the first irradiation time at the first emission intensity, and the valuable excited by the excitation light irradiated in the first excitation light irradiation step The first light emission amount measuring step for measuring the light emission amount from the medium and the second light irradiation time that is different from the length of the first irradiation time, and the same amount of light as the excitation light irradiated in the first excitation light irradiation step. A second excitation light irradiation step of irradiating the valuable medium with excitation light at a second emission intensity set to be, and the valuable excited by the excitation light irradiated in the second excitation light irradiation step Second luminescence measurement to measure luminescence from the medium Comparing the measurement result obtained in the step and the first luminescence measurement step with the measurement result obtained in the second luminescence measurement step, the emission from the valuable medium is either fluorescence or phosphorescence. And a light emission determination step of determining whether or not there is a feature.

Further, in the present invention according to the present invention, in the emission determination step, the first emission amount measured in the first emission amount measurement step and the second emission amount measured in the second emission amount measurement step are the same. In the case where the emission from the valuable medium is determined to be fluorescence emission, and the first emission amount and the second emission amount are different, the emission from the valuable medium is phosphorescence emission. It is determined that it exists.

Further, according to the present invention, in the above-described invention, in the light emission determination step, when the first light emission amount and the second light emission amount are different, the first light emission amount and the second light emission amount are compared and phosphorescence is compared. The type of light emission is identified.

The present invention also relates to a fluorescence / phosphorescence detection device that detects fluorescence emission and phosphorescence emission having different time characteristics of emission intensity when irradiated with the same excitation light, and is a light source that irradiates a valuable medium with excitation light. In addition, during the first irradiation time, the excitation light is irradiated with the first emission intensity, and during the second irradiation time different from the time length of the first irradiation time, the first irradiation time and the first emission intensity. A light source control unit that controls the light source so as to irradiate excitation light with a second light emission intensity that is set to have the same light amount as the excitation that is irradiated; a sensor that measures light emission excited by the valuable medium; The first emission intensity obtained by measuring the emission emitted by the first emission intensity and the excitation light of the first irradiation time by the sensor, and the excitation light of the second emission intensity and the second irradiation time. The excited luminescence is measured by the sensor Obtained by comparing the second light emission amount, light emitted from the valuable medium is characterized by comprising a fluorescence emission and determining emission determination unit which of phosphorescent.

In the present invention, the light emission determination unit determines that the light emission from the valuable medium is a fluorescence light emission when the first light emission amount and the second light emission amount are the same. When the first light emission amount and the second light emission amount are different, it is determined that light emission from the valuable medium is phosphorescence light emission.

Further, according to the present invention, in the above invention, the light emission determination unit compares the first light emission amount with the second light emission amount when the first light emission amount and the second light emission amount are different from each other. The type of light emission is identified.

Further, according to the present invention, in the above invention, a light source filter that transmits the excitation light from the light source side to the valuable medium side and blocks light emission from the valuable medium side to the light source side, and an excitation light from the light source. A light source monitor sensor provided in the vicinity of the light source on the light source side for monitoring irradiation, and a timing control unit for determining a control timing of the light source based on an output from the light source monitor sensor The light source control unit is controlled by the timing control unit.

In addition, the present invention detects the authenticity of a valuable medium by detecting fluorescence emission and phosphorescence emission having different time characteristics of emission intensity when irradiated with the same excitation light, and determining the authenticity of the valuable medium based on the detection result A first excitation light irradiation step of irradiating a valuable medium with excitation light for a first irradiation time at a first emission intensity, and excitation by the excitation light irradiated in the first excitation light irradiation step A first light emission measuring step for measuring the amount of light emitted from the valuable medium, and the excitation light irradiated in the first excitation light irradiation step during a second irradiation time different from the length of the first irradiation time; Excited by the second excitation light irradiation step of irradiating the valuable medium with the excitation light at the second emission intensity set to have the same light amount and the excitation light irradiated in the second excitation light irradiation step. The second measurement that measures the amount of light emitted from the valuable medium Comparing the measurement result obtained in the measurement step and the first luminescence measurement step with the measurement result obtained in the second luminescence measurement step, the emission from the valuable medium is either fluorescence emission or phosphorescence emission. A fluorescence / phosphorescence determination step for determining whether or not the authenticity of the valuable medium is determined based on a determination result in the fluorescence / phosphorescence determination step.

In addition, the present invention detects the authenticity of a valuable medium by detecting fluorescence emission and phosphorescence emission having different time characteristics of emission intensity when irradiated with the same excitation light, and determining the authenticity of the valuable medium based on the detection result A light source for irradiating the valuable medium with the excitation light and the second irradiation different from the time length of the first irradiation time while irradiating the excitation light with the first emission intensity during the first irradiation time; A light source control unit that controls the light source so as to irradiate the excitation light with the second light emission intensity set so as to have the same light amount as the excitation irradiated with the first irradiation time and the first light emission intensity during the time. A sensor for measuring the light emission excited by the valuable medium, the light emission amount obtained by measuring the light emission excited by the excitation light of the first light emission intensity and the first irradiation time by the sensor, Excitation of second emission intensity and second irradiation time A light emission determination unit that compares the light emission amount obtained by measuring the light emission excited by the sensor with the light emission amount to determine whether the light emission from the valuable medium is fluorescent light emission or phosphorescence light emission; and A true / false determination unit that determines the authenticity of the valuable medium based on a determination result by the determination unit.

According to the present invention, the excitation light is irradiated a plurality of times with different irradiation times, but the light emission intensity of each irradiation is set so that the light emission amount is the same. By comparing these, it is possible to determine whether this emission is fluorescence emission or phosphorescence emission. Whether the valuable medium emits fluorescent light or phosphorescent light can be detected with high accuracy. Therefore, the authenticity of the valuable medium can be determined based on whether light emission to be detected from the valuable medium is detected.

In addition, according to the present invention, not only the difference between fluorescence and phosphorescence but also the kind of phosphorescence can be identified from the difference in the amount of emitted light excited by the valuable medium in each irradiation. Thereby, for example, even when a valuable medium is forged and phosphorescence emission different from the true valuable medium is detected in the valuable medium, the authenticity determination of the valuable medium is performed based on the difference in the type of phosphorescence emission. be able to.

FIG. 1 is a diagram for explaining the relationship between excitation light applied to a valuable medium and fluorescence emission and phosphorescence emission excited by the excitation light. FIG. 2 is a diagram showing the relationship between the irradiation time and the light emission amounts of fluorescence, phosphorescence A and phosphorescence B when the irradiation time and light emission intensity are changed so that the same light emission amount is obtained and the excitation light is irradiated. FIG. 3 shows sensor output integrated values obtained by excited fluorescence, phosphorescence A, and phosphorescence B when irradiation with excitation light is performed twice while changing the irradiation time and emission intensity so as to achieve the same light emission amount. FIG. FIG. 4 is a schematic cross-sectional view illustrating the structural outline of the fluorescence / phosphorescence detection apparatus according to the first embodiment. FIG. 5 is a functional block diagram for explaining the functional outline of the fluorescence / phosphorescence detection apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an example of the circuit configuration of the integrator. FIG. 7 is a diagram for explaining a method for measuring luminescence excited by a valuable medium by the fluorescence / phosphorescence detection apparatus according to the first embodiment. FIG. 8 is a functional block diagram for explaining the functional outline of the fluorescence / phosphorescence detection apparatus according to the second embodiment. FIG. 9 is a diagram for explaining a method for measuring luminescence excited by a valuable medium by the fluorescence / phosphorescence detection apparatus according to the second embodiment. FIG. 10 is a diagram for explaining an example in which the irradiation of excitation light in the fluorescence / phosphorescence detection apparatus is controlled by the shutter unit.

With reference to the accompanying drawings, a fluorescence / phosphorescence detection method and a fluorescence / phosphorescence detection apparatus according to the present invention, and a true / false determination method for determining the authenticity of a valuable medium based on a detection result by the fluorescence / phosphorescence detection method And a preferred embodiment of the apparatus will be described in detail. According to the fluorescence / phosphorescence detection method and the fluorescence / phosphorescence detection apparatus according to the present embodiment, for example, the fluorescence / phosphorescence emitted by excitation light such as ultraviolet light (UV light) is emitted at a wavelength different from the excitation light. Can be detected. Further, in the fluorescence / phosphorescence detection method according to the present embodiment, it is possible to detect the presence / absence of fluorescence emission ink and phosphorescence emission ink used in valuable media such as banknotes, checks, gift certificates, cards and the like.

In the fluorescence / phosphorescence detection method according to the present embodiment, a light source is irradiated with excitation light for exciting fluorescence emission and phosphorescence emission from a light source a plurality of times under different conditions. Measure with And based on each measurement result obtained by multiple times of irradiation, it is determined whether the light emission measured by the valuable medium is fluorescence emission or phosphorescence emission. In the following, first, the fluorescence / phosphorescence detection method will be described with reference to FIG.

FIG. 1 is a diagram for explaining the relationship between excitation light applied to a valuable medium to excite fluorescence and phosphorescence, and fluorescence emission and phosphorescence emission excited by the excitation light. FIG. 1A shows the emission intensity and irradiation timing of irradiation light irradiated as excitation light from a light source. In addition, the left figure of FIG. 1 (b) shows the temporal characteristics of the fluorescence emission excited on the valuable medium by the irradiation light shown in FIG. 1 (a), and the right figure shows the measurement of the fluorescence emission. The integrated value (light emission amount) of the obtained sensor output is shown. Similarly, the left figure of FIG. 1 (c) shows the time characteristics of phosphorescence emission excited on the valuable medium by the irradiation light shown in FIG. 1 (a), and the right figure shows the phosphorescence emission measurement. It shows the integrated value (light emission amount) of the sensor output obtained at the time. Here, the sensor includes, for example, an LED that emits excitation light having a UV wavelength and a photodiode that measures the excited light emission.

In FIG. 1A and the left diagrams of FIGS. 1B and 1C, the vertical axis indicates the emission intensity and the horizontal axis indicates time. In addition, the right diagrams of FIGS. 1B and 1C show the integrated values of sensor outputs obtained by measuring the luminescence excited during the first and second irradiations.

Since the unit of emission intensity depends on the measurement system that measures light, the unit is omitted in this embodiment, but the emission intensity of irradiation light is, for example, an LED whose emission intensity increases linearly according to the applied current value. This corresponds to the current value applied to the light source. The emission intensity of fluorescence and phosphorescence is a sensor using an element such as a photodiode whose current amount increases linearly according to the received emission intensity, and corresponds to the current value output from the sensor.

As shown in FIG. 1A, in the first and second irradiations, the excitation light is irradiated so that the light emission amounts are the same while changing the light emission intensity and the irradiation time. Specifically, at the first time, excitation light with emission intensity H is irradiated for the irradiation time T (t0 to t1). In the second time, excitation light having an emission intensity of n × H is irradiated for the irradiation time T / n (t2 to t3).

Here, n is, for example, a natural number of 2 or more, and the second irradiation indicates that the irradiation is performed for a short time of 1 / n compared to the first irradiation. While the irradiation time for the second time is shorter than that for the first time, the light emission intensity for the second time is set to n times the light emission intensity for the first time. Thereby, in FIG. 1A, the light emission amount of each irradiation light indicated by the integral value becomes HT (= H × T) in the first irradiation, and HT (= (n × H) in the second irradiation. X (T / n)). That is, by adjusting the light emission intensity while setting the irradiation time of the second irradiation light to be shorter than the first irradiation time, the light emission amounts of the second irradiation light and the first irradiation light are made the same. is there.

When ink that fluoresces fluorescent light is used as a valuable medium, when two excitation light irradiations with different irradiation times and emission intensities are performed as shown in FIG. 1A, the left figure of FIG. Thus, fluorescence emission is observed. In the first irradiation, the fluorescence is excited simultaneously with the start of the excitation light irradiation, and this fluorescence emission is observed for a time T (t0 to t1) until the excitation light irradiation is stopped. In the second irradiation, the fluorescence is excited at the same time as the start of the excitation light irradiation, and this fluorescence emission is observed for a time T / n (t2 to t3) until the irradiation is stopped. Thus, in fluorescence emission, light emission starts simultaneously with the excitation light irradiation, and disappears at the same time as the excitation light irradiation is stopped.

In the fluorescence emission, as shown in the left diagram of FIG. 1B, a constant emission intensity is maintained while the excitation light is irradiated. The emission intensity varies depending on the ink characteristics and the like, but is an intensity corresponding to the emission intensity of the excitation light. Specifically, as shown in the left diagram of FIG. 1 (b), when the fluorescence having the emission intensity Ha is observed by the first irradiation with the emission intensity H, the second irradiation with the emission intensity n × H is performed. The intensity of fluorescence emission is n × Ha.

As a result, as indicated by hatching in the left diagram of FIG. 1B, the light emission amount obtained by the first irradiation is Ha × T, and the light emission amount obtained by the second irradiation is also Ha × T (= (n × Ha) × (T / n)). As described above, when the irradiation time is changed between the first irradiation and the second irradiation and the emission intensity is set so that the light emission amount becomes the same value (HT) and the excitation light is irradiated, the fluorescence emission is the first time. The amount of fluorescent light emission obtained by the irradiation of 2 and the amount of fluorescent light emission obtained by the second irradiation become the same value (Ha × T). For this reason, when integrating the sensor output that receives the fluorescence emission excited by the first irradiation and the second irradiation, the same integrated value (Sa) is obtained as shown in the right diagram of FIG. Become.

When a phosphorescent light-emitting ink is used as a valuable medium, as shown in FIG. 1 (a), if irradiation is performed twice with different irradiation times and light emission intensities, as shown in FIG. Phosphorescence emission is observed.

In the first irradiation, phosphorescence emission starts simultaneously with the start of excitation light irradiation (t0), and then the emission intensity gradually increases (becomes bright) and eventually reaches a saturated state. Then, phosphorescence emission is observed even after irradiation of excitation light is stopped (t1), but the emission intensity gradually decreases (darkens), and eventually disappears. Even in the second irradiation, after the irradiation is started (t2), the emission intensity of phosphorescence gradually increases. When the emission intensity of the excitation light to be irradiated is strong, the emission intensity of phosphorescence emission may increase even after the irradiation is stopped. The second phosphorescence emission in the left figure of FIG. 1 (c) shows such a case. After the emission intensity rises after the excitation light irradiation is stopped (t3) (t4), the light emission is gradually emitted. The strength decreases and eventually disappears.

The emission intensity at the time of saturation of phosphorescence varies depending on the characteristics of the ink and the like. For example, as shown in the left diagram of FIG. 1C, when the saturation state is reached by the first irradiation of the emission intensity H (t1) When the phosphorescence emission intensity is Hb and the phosphorescence emission intensity when the saturation state is reached after the second irradiation of the emission intensity n × H (t4) is Hd, the emission intensity has a relationship of Hb <Hd. The emission intensity Hc at (t3) when the second irradiation is stopped is lower than the emission intensity Hd.

As a result, as is apparent from the area of the shaded area in FIG. 1 (c), the light emission amount obtained by the second irradiation is lower than the light emission amount obtained by the first irradiation. Value. As described above, in phosphorescence emission, when the irradiation time is changed between the first irradiation and the second irradiation and the emission intensity is set so that the light emission amount becomes the same value (HT), the excitation light is irradiated. The amount of phosphorescence emitted by the second irradiation is different from the amount of phosphorescence obtained by the second irradiation. For this reason, when integrating the sensor output that receives the phosphorescence emitted excited by the first irradiation and the second irradiation, different integration values (Sb and Sc) are obtained as shown in the right diagram of FIG. It will be.

As shown in FIG. 1A, by irradiating the excitation light in multiple times so that the light emission amount is the same while changing the irradiation time and the light emission intensity, As shown in the right figure, in the case of fluorescent light emission, the integrated value (light emission amount) of the sensor output becomes the same value for each irradiation, and in the case of phosphorescent light emission, the integrated value (light emission amount) of the sensor output becomes a different value. For this reason, based on the output value of the sensor obtained by measuring the excited luminescence, it is possible to accurately determine whether the emission is fluorescence or phosphorescence.

Specifically, in the fluorescence / phosphorescence detection method according to the present embodiment, the irradiation light is irradiated twice as shown in FIG. 1A, and the integrated value of the signal output from the sensor is within a predetermined error range. If they coincide with each other, it is determined that the light emission is the fluorescence emission shown in the right figure (b). To do.

Note that the first irradiation time (T) and the second irradiation time (T / n) are set such that the amount of phosphorescence emission differs between the first and second irradiations according to the emission characteristics of phosphorescence. That is, the integral values of the sensor outputs obtained by measuring phosphorescence are set to be different.

Further, the time (t1 to t2) from the end of the first excitation light irradiation shown in FIG. 1A to the start of the second irradiation (t1 to t2) is, for example, that phosphorescence emitted by the first irradiation is phosphorescence. It is set according to the disappearance time. Specifically, as shown in FIG. 1 (c), after the first irradiation is stopped (t1), the phosphorescence decays to 0 (zero) (t2), or thereafter, the second time. Start irradiation. However, if phosphorescence emission is measured in the first and second irradiations and different sensor output integration values can be obtained each time, the second irradiation is started without waiting for the disappearance of phosphorescence after the first irradiation. May be.

Although FIG. 1 shows a method for determining whether fluorescence emission or phosphorescence emission is based on the difference in temporal characteristics of emission intensity between fluorescence emission and phosphorescence emission, the fluorescence / phosphorescence according to the present embodiment is shown. According to the detection method, it is also possible to distinguish between the different types of phosphorescence emission. Specifically, the sensor output integral value shown in the right diagram of FIG. 1 (c) shows different values depending on the time characteristics of phosphorescence emission shown in the left diagram of the figure, so that the first and second sensor output integral values, Based on the difference or ratio of the integral values, the difference in the type of phosphorescence emission can be identified. Hereinafter, a method for identifying the type of phosphorescence emission will be described.

FIG. 2 shows the amount of emission of fluorescence, phosphorescence A and phosphorescence B excited by the excitation light, and the amount of excitation light when the emission intensity is set so that the irradiation time of the excitation light is changed and the same emission amount is obtained. It is a figure which shows the relationship with irradiation time. Further, FIG. 3 shows that the fluorescence, phosphorescence A, and phosphorescence B having the characteristics shown in FIG. 2 are irradiated twice by changing the irradiation time of the excitation light and setting the emission intensity so that the emission amount is the same. It is a figure which shows the integrated value of the sensor output obtained by measuring the light excited by each irradiation in the case of.

2 and 3 show the results of normalizing the emission amounts of phosphorescence A and phosphorescence B based on the emission amount of fluorescence. Also, the same reference numerals Pn (n = 1 to 7) are attached to the values corresponding to those in FIGS.

When the first irradiation time is set to 200 μsec and the second irradiation time is set to 100 μsec when the excitation light is irradiated twice, the fluorescence, phosphorescence A, and phosphorescence B excited by each irradiation are shown in FIG. The sensor output integral value shown in a) is obtained. When the first irradiation time is set to 500 μsec and the second irradiation time is set to 100 μsec, the sensor output integrated value shown in FIG. 3B is obtained.

When the result shown in FIG. 3A is obtained, the sensor output values obtained by the first irradiation and the second irradiation are compared, and the light emission having substantially the same sensor output integrated value is emitted by fluorescence and sensor output integration. It is possible to distinguish between phosphorescence A when the difference in value is the value d1 and phosphorescence B as the emission whose difference in the sensor output integral value is the value d2 and the type of emission. In addition, fluorescence, phosphorescence A, and phosphorescence B can be identified from the value of the sensor output integral value obtained by each irradiation and the ratio of the first and second sensor output integral values.

Also, when the result shown in FIG. 3B is obtained, the fluorescence, phosphorescence A and the difference between the sensor output integrated value obtained by each irradiation and the difference or ratio between the first and second sensor output integrated values are also obtained. Phosphorescence B can be identified. Furthermore, in the example of FIG. 3B, the irradiation time is set so that the first sensor output integral value is substantially the same for fluorescence, phosphorescence A and phosphorescence B, so the second sensor output integral value. Based on the comparison result, fluorescence, phosphorescence A and phosphorescence B can also be distinguished.

Thus, according to the fluorescence / phosphorescence detection method according to the present embodiment, not only fluorescence emission and phosphorescence emission can be distinguished, but also the type of phosphorescence emission can be identified. Thus, when phosphorescence emission different from the true valuable medium 100 is observed, it can be determined that the valuable medium 100 is a counterfeit medium.

Next, a specific example of a fluorescence / phosphorescence detection apparatus that realizes such a fluorescence / phosphorescence detection method will be described. FIG. 4 is a schematic cross-sectional view showing an outline of the structure of the fluorescence / phosphorescence detection device 10. The fluorescence / phosphorescence detection device 10 has an opening window 6a made of a transparent member such as glass on the upper surface side of the sensor case through which the valuable medium 100 passes, and the inner space of the sensor case is a partition plate that blocks light. 6b is divided into a light source side (right side in FIG. 4) and a light emission detection sensor side (left side in FIG. 4).

The valuable medium 100 is conveyed above the fluorescence / phosphorescence detection device 10 in the conveyance direction 200 by a conveyance mechanism including a roller (not shown). For example, a signal related to the conveyance timing by the conveyance mechanism is input to the fluorescence / phosphorescence detection device 10, and processing for detecting fluorescence / phosphorescence is performed on a predetermined area on the valuable medium 100 based on this signal. Specifically, excitation light irradiation and light emission detection are performed in accordance with the timing at which the region where fluorescence or phosphorescence is excited on the valuable medium 100 by the excitation light passes through the detection region by the fluorescence / phosphorescence detection device 10. Processing is performed. In addition, about the detail of a conveyance mechanism and the method of processing according to the conveyance timing by a conveyance mechanism, since the prior art utilized with a banknote processing apparatus etc. can be utilized, detailed description is abbreviate | omitted.

In the space on the light source side, a light source 1 for irradiating ultraviolet light as excitation light and a light source filter 3 for allowing only ultraviolet light irradiated from the light source 1 to pass through are provided. The light source 1 is an LED 1a that irradiates ultraviolet light toward the valuable medium 100 conveyed in the conveying direction 200 above the opening window 6a, and a light source monitor for monitoring the emission intensity of the ultraviolet light emitted from the LED 1a. And a sensor 1b. Due to the partition plate 6b, the ultraviolet light emitted from the LED 1a does not directly reach the space on the light emission detection sensor side. Even when visible light or infrared light is emitted from the valuable medium 100 due to ultraviolet light from the LED 1a, the light source filter 3 prevents this light from reaching the light source monitor sensor 1b. The light emitted from the LED 1a can be accurately monitored using 1b.

On the other hand, in the space on the light emission detection sensor side, the measurement filter 4 that blocks the ultraviolet light irradiated from the LED 1a and transmits the light emitted by the valuable medium 100, and the measurement filter 4 from the opening window 6a. A light receiving unit 2 that receives incident light is provided. The measurement filter 4 has a function of transmitting only fluorescence and phosphorescence excited by the valuable medium 100. For example, when the fluorescence emission is visible light and the phosphorescence emission is infrared light, the measurement filter 4 does not transmit light in the wavelength range of ultraviolet light, which is excitation light, and does not transmit visible light and infrared light. Transmits only light in the wavelength range.

The light receiving unit 2 includes a light emission measuring sensor 2b for measuring the light emission amount of incident light, and a condenser lens 2a for condensing the light transmitted through the measurement filter 4 on the light emission measuring sensor 2b. Have. The light emission measuring sensor 2b can detect even weak light emission by the light collecting function of the condenser lens 2a. If the emission intensity of the light excited by the valuable medium 100 is sufficiently high and can be measured accurately without the condensing lens 2a, the fluorescence / phosphorescence detection device 10 does not have the condensing lens 2a. It may be a structure.

The LED 1a, the light source monitoring sensor 1b, and the light emission measuring sensor 2b are connected to a common substrate 5, respectively. Based on a control signal input to the substrate 5 from the outside, the LED 1a is controlled by the light source monitoring sensor 1b. The irradiation light from the LED 1a is monitored, and the fluorescence emission and phosphorescence emission are measured by the emission measurement sensor 2b.

FIG. 5 is a functional block diagram for explaining the functions of the fluorescence / phosphorescence detection apparatus 10. The substrate 5 of the fluorescence / phosphorescence detection device 10 controls the light source control unit 11 for controlling the LED 1a, the emission intensity and irradiation timing of the excitation light emitted from the LED 1a, and the measurement timing using the light emission measuring sensor 2b. A timing control unit 12, an integrator 14 for acquiring an integrated value from the output signal of the light emission measuring sensor 2b, an integrator 15 for acquiring an integrated value from the output signal of the light source monitoring sensor 1b, A light emission determining unit 13 is provided for determining whether light emitted from the valuable medium 100 upon receiving the output from the integrator 14 is fluorescent light emission or phosphorescent light emission and outputting the light emission.

The light emission determination unit 13 includes, for example, a CPU, a memory, a sample hold circuit, an A / D converter, and the like. Then, when the excitation light is irradiated a plurality of times from the LED 1a toward the valuable medium 100, the function of determining the type of light emission by reading and comparing the sensor output integrated value at each light irradiation obtained by the light emission measurement sensor 2b. Have The determination result by the light emission determination unit 13 is input to the authenticity determination unit 30, for example.

The authenticity determination unit 30 includes, for example, a CPU and a memory, and has a function of determining the authenticity of the valuable medium 100 based on the fluorescence / phosphorescence distribution information stored in the memory in advance and the determination result by the light emission determination unit 13. Here, the fluorescence / phosphorescence distribution information is information relating to the type of fluorescence / phosphorescence detected on the true valuable medium 100 and the position on the valuable medium 100. The authenticity determination unit 30 specifies the position of the valuable medium 100 that is transported by the transport mechanism and passes above the fluorescence / phosphorescence detection device 10 in cooperation with a transport mechanism (not shown), and is obtained at the specified position. It is determined whether the result of the light emission determination by the light emission determination unit 13 matches the fluorescence / phosphorescence distribution information. When the fluorescence emission is detected at the position where the fluorescence emission on the valuable medium 100 should be observed, the valuable medium 100 is determined to be the true valuable medium 100. Similarly, when phosphorescence emission is detected at a position where phosphorescence emission should be observed on the valuable medium 100, it is determined that the medium is a true valuable medium 100.

Thus, the authenticity determination device of the valuable medium 100 can be realized by adding the authenticity determination unit 30 to the fluorescence / phosphorescence detection device 10. In this case, for example, the determination result obtained by the authenticity determination device is output from the authenticity determination unit 30 to the outside. The authenticity determination device including the fluorescence / phosphorescence detection device 10 and the authenticity determination unit 30 is used, for example, in a valuable medium processing apparatus that identifies and counts the valuable medium 100.

FIG. 6 is a circuit diagram illustrating a configuration example of the

integrators

14 and 15 used in the fluorescence / phosphorescence detection device 10. Thus, for example, an integration circuit composed of a capacitor (C) and an operational amplifier (OPAMP), a reset circuit composed of a CMOS switch (SWITCH) and a resistor (R1) for discharging the capacitor charge, resistors (R2, R3) and

Integrators

14 and 15 are formed by adding a drive circuit that is composed of a transistor (TR) and drives the reset circuit. Then, the integrated values obtained by receiving signals output from the light emission measuring sensor 2b and the light source monitoring sensor 1b formed using, for example, a photodiode (PD) are output as Vo and

integrators

14 and 15 respectively. Is output from. In the

integrators

14 and 15, since the output signal from the sensor is accumulated as an integrated value, the accumulated signal is reset in response to an external reset signal.

FIG. 7 is a diagram for explaining a method of measuring luminescence excited by the valuable medium 100 by the fluorescence / phosphorescence detection device 10. Hereinafter, details of the measurement method of light emission performed by each functional unit shown in FIG. 5 will be described.

First, the timing control unit 12 inputs a signal to the light source control unit 11 to instruct the LED 1a as the light source to be turned on with the emission intensity H and to start the irradiation of the excitation light. In response to this, the light source controller 11 turns on the LED 1a with the emission intensity H as shown in FIG. 7A (t10). Further, the timing control unit 12 inputs a reset signal to the

integrators

14 and 15 as shown in FIG. 7B simultaneously with the lighting instruction to the light source control unit 11.

When the integrator 15 receives the reset signal, the output value is reset to 0 (zero) at the timing (t10) when the LED 1a is turned on, as shown in FIG. Then, the integrator 15 starts outputting a signal obtained by integrating the signal from the light source monitor sensor 1b (t10). This output signal is input to the timing control unit 12.

On the other hand, also in the integrator 14 that has received the reset signal, the output value is reset to 0 (zero) at the timing (t10) when the LED 1a is turned on, as shown in FIG. When the valuable medium 100 emits light in response to excitation light from the LED 1a, a signal is output from the light emission measuring sensor 2b in response to this light emission. Then, the integrator 14 starts outputting a signal obtained by integrating the signal from the light emission measurement sensor 2b (t10). An output signal from the integrator 14 is input to the light emission determination unit 13. FIG. 7E shows an output signal from the integrator 14 when the light emission excited by the valuable medium 100 is fluorescence light emission.

The timing controller 12 monitors the output signal of FIG. 7C obtained from the light source monitor sensor 1b via the integrator 15 as a signal for monitoring the light emission amount of the LED 1a. Then, when the value of the output signal reaches a preset trigger threshold value (t11) as shown in FIG. 7C, the timing control unit 12 sends the light source control unit 11 to the light source control unit 11 from the LED 1a. A signal for instructing stop of excitation light irradiation is input. At the same time, the timing control unit 12 inputs a trigger signal shown in FIG. 7D to the light emission determination unit 13 (t11).

Upon receiving this, the light source control unit 11 turns off the LED 1a (FIG. 7 (a) t11). Moreover, the light emission determination part 13 hold | maintains the output value from the integrator 14 as a sensor output integrated value by the 1st irradiation at the timing which received the trigger signal (FIG.7 (e) t11).

The trigger threshold shown in FIG. 7C is set based on the emission amount HT of excitation light. In the first irradiation performed at the emission intensity H as shown in FIG. 7A, as shown in FIG. 7C, when the time T has elapsed from the start of the irradiation, the integrator 15 The output value reaches the trigger threshold. On the other hand, in the second irradiation performed at the emission intensity of 2H, the output value from the integrator 15 reaches the trigger threshold when the time T / 2 has elapsed since the irradiation was started. Thereby, the extinction timing of LED1a can be controlled based on the output value from the integrator 15, and excitation light irradiation of each time shown to Fig.7 (a) is realizable.

When the first excitation light irradiation is finished, the timing controller 12 then counts the time (t11) after turning off the LED 1a, and at the timing when a predetermined time has passed (t12), the emission intensity is 2H. The LED 1a is turned on, and a signal instructing to start excitation light irradiation is input to the light source control unit 11. Further, the timing control unit 12 inputs a reset signal to the

integrators

14 and 15 as shown in FIG. 7B simultaneously with the lighting instruction to the light source control unit 11 (t12).

In response to this, the light source controller 11 turns on the LED 1a again at the emission intensity of 2H and starts the second irradiation (FIG. 7 (a) t12). Further, the

integrators

14 and 15 are reset in the same manner as in the first irradiation, and start output of integrated values by the second irradiation (FIG. 7 (c) t12 and FIG. 7 (e) t12).

In the second irradiation, since the light emission intensity of the LED 1a is twice the first light emission intensity, the output signal obtained from the light source monitor sensor 1b via the integrator 15 is half the time (T / 2). ) To reach the trigger threshold (FIG. 7 (c) t13). When the trigger threshold value is reached, the timing control unit 12 inputs a signal that instructs the light source control unit 11 to turn off the LED 1a, and simultaneously inputs a trigger signal to the light emission determination unit 13 (FIG. 7D). t13).

Upon receiving this, the light source control unit 11 turns off the LED 1a (FIG. 7 (a) t13). Moreover, the light emission determination part 13 hold | maintains the output value from the integrator 14 as a sensor output integrated value by the 2nd irradiation at the timing which received the trigger signal (FIG.7 (e) t13).

Then, the light emission determination unit 13 compares the sensor output integrated value obtained at the time of the first irradiation with the sensor output integrated value obtained at the time of the second irradiation. It is determined whether the emission is phosphorescence or phosphorescence, and the determination result is output to the outside. Specifically, as described with reference to the right diagrams of FIGS. 1B and 1C, the first sensor output integrated value and the second sensor output integrated value are within a predetermined error range. If they coincide with each other, it is determined that the fluorescence is emitted, and if there is a difference exceeding the error range, it is determined that the emission is phosphorescence. In FIG. 7 exemplifying the case of fluorescence emission, the output value at time t11 and the output value at time t13 shown in FIG. 7E are the same value, so that the emission emitted by the valuable medium 100 is fluorescence emission. It is determined that there is.

7 shows an example in which fluorescence emission is detected by the valuable medium 100. However, when phosphorescence emission is detected, the output waveform from the integrator 14 shown in FIG. 7 (e) has a different shape. As shown in the right diagram of FIG. 1C, the output value obtained by the second irradiation is lower than the output value obtained by the first irradiation. Further, when neither fluorescence emission nor phosphorescence emission is observed in the valuable medium 100, that is, when light is not excited, the output waveform from the integrator 14 shown in FIG. 7E remains 0 (zero). .

In addition, in this embodiment, for the sake of simplicity, an embodiment is shown in which the process of measuring the emitted light by irradiating the excitation light twice is performed only once, but the process is repeated a plurality of times. It may be a mode to be described. One excitation light irradiation is executed in a short time, for example, in microseconds. Therefore, in the fluorescence / phosphorescence detection apparatus 10, as shown in FIG. 4, the process shown in FIG. 7 can be repeatedly performed while the valuable medium 100 conveyed in the conveyance direction 200 passes above the apparatus. Then, it can be determined whether fluorescence and phosphorescence are excited at each position on the valuable medium 100. Thus, the authenticity of the valuable medium 100 is determined based on whether the fluorescent light emission is detected at the position where the fluorescent light emission should be detected on the valuable medium 100 or the phosphorescent light emission is detected at the position where the phosphorescent light emission should be detected. Judgment can be made.

In the first embodiment, the timing of turning off the LED 1a serving as the light source is controlled by monitoring the light emission amount from the LED 1a, but the method of controlling the light source is not limited to this. For example, the lighting of the LED 1a may be controlled based on the irradiation time.

In the present embodiment, the case where the fluorescence / phosphorescence detection device 10 has a configuration in which the light source monitor sensor 1b and the light source filter 3 are removed from the configuration shown in FIG. 4 will be described. In the following, description of the same configuration and operation as in the first embodiment will be omitted, and description will be continued focusing on differences from the first embodiment.

FIG. 8 is a functional block diagram for explaining functions of the fluorescence / phosphorescence detection apparatus 10 according to the present embodiment. The fluorescence / phosphorescence detection apparatus 10 according to the present embodiment controls the light source control unit 11 for controlling the LED 1a, the emission intensity and irradiation timing of the irradiation light from the LED 1a, and the measurement timing using the light emission measuring sensor 2b. A timing control unit 12 for the output, an integrator 14 for obtaining an integral value from an output signal of the light emission measuring sensor 2b, and light emitted from the valuable medium 100 in response to an output from the integrator 14 is emitted by fluorescence. And a light emission determination unit 13 for determining and outputting the phosphorescence emission.

FIG. 9 is a diagram for explaining a method of measuring light emission excited by the valuable medium 100 by each functional unit shown in FIG. First, the timing control unit 12 inputs a signal instructing to start the irradiation of excitation light with the emission intensity H to the light source control unit 11. In response to this, the light source control unit 11 turns on the LED 1a with the emission intensity H as shown in FIG. 9A (t10). Further, the timing control unit 12 inputs a reset signal to the integrator 14 as shown in FIG. 9B simultaneously with the lighting instruction to the light source control unit 11.

Upon receiving the reset signal, the integrator 14 resets the output value to 0 (zero) at the timing (t10) when the LED 1a is turned on, as shown in FIG. 9 (c). When the valuable medium 100 emits light upon receiving light from the LED 1a, a signal is output from the light emission measuring sensor 2b upon receiving this light emission. Then, the integrator 14 starts outputting a signal obtained by integrating the signal from the light emission measurement sensor 2b (t10). An output signal from the integrator 14 is input to the light emission determination unit 13. FIG. 9C shows an output signal from the integrator 14 when the light emission in the valuable medium 100 is fluorescent light emission.

The timing control unit 12 counts the time after the LED 1a is turned on. When the time T elapses after the LED 1a is turned on (FIG. 9 (a) t11), a signal instructing the light source controller 11 to turn off the LED 1a is input. At the same time, the timing control unit 12 inputs the trigger signal shown in FIG. 9D to the light emission determination unit 13 (t11).

Upon receiving this, the light source control unit 11 turns off the LED 1a (FIG. 9 (a) t11). Moreover, the light emission determination part 13 hold | maintains the output value from the integrator 14 as a sensor output integrated value by the 1st irradiation at the timing which received the trigger signal (FIG.9 (c) t11).

Subsequently, the timing control unit 12 counts the time (t11) after the LED 1a is turned off, and a signal instructing to start the irradiation of the excitation light with the emission intensity 2H at the timing when the predetermined time has elapsed (t12). Is input to the light source control unit 11. Further, the timing control unit 12 inputs a reset signal to the integrator 14 as shown in FIG. 9B simultaneously with the lighting instruction to the light source control unit 11 (t12).

In response to this, the light source controller 11 turns on the LED 1a again at the emission intensity of 2H and starts the second irradiation (FIG. 9 (a) t12). Further, the integrator 14 is reset in the same manner as at the time of the first irradiation, and starts to output an integrated value by the second irradiation (FIG. 9 (c) t12).

Then, as in the first irradiation, the timing controller 12 counts the time since the LED 1a is turned on, and when the time T / 2 has elapsed from the start of lighting (FIG. 9 (a) t13), the light source A signal that instructs the controller 11 to turn off the LED 1a is input. At the same time, the timing control unit 12 inputs a trigger signal to the light emission determination unit 13 (FIG. 9 (d) t13).

In response to this, the light source control unit 11 turns off the LED 1a (FIG. 9 (a) t13), and the light emission determination unit 13 receives the trigger signal (FIG. 9 (c) t13) and outputs an output value from the integrator 14. Is held as a sensor output integrated value by the second irradiation.

In this way, when the sensor output integrated value obtained at the first irradiation and the sensor output integrated value obtained at the second irradiation are obtained by the light emission determination unit 13, as in the case of the first embodiment, the fluorescence is emitted. Processing for determining light emission and phosphorescence emission can be performed.

Thus, if the light emission intensity and irradiation time of LED1a which irradiates excitation light are controlled by the timing control part 12 and the light source control part 11, an Example will be performed, without monitoring the light emission amount of LED1a like Example 1. FIG. As in the case of No. 1, the valuable medium 100 can be irradiated with excitation light with different emission intensity and irradiation time for the first time and the second time. Then, the luminescence excited by the valuable medium 100 can be measured by the luminescence measurement sensor 2b, and it can be determined whether the luminescence is fluorescence emission or phosphorescence emission.

In addition, in the present Example, although the aspect which directly controls the light emission intensity and lighting time of LED1a which irradiate excitation light was shown, the control method of excitation light is not limited to this. FIG. 10 is a diagram for explaining an example in which the irradiation of excitation light is controlled by the shutter unit.

For example, as shown in FIG. 10A, a shutter unit 110a for controlling the passage and blocking of this light is arranged on the optical path where the excitation light irradiated from the LED 1a reaches the valuable medium 100. The timing control unit 12 controls the light emission intensity from the LED 1 a via the light source control unit 11 and controls the shutter unit 110 a via the shutter control unit 121. If the passage and blocking of light from the LED 1a are controlled by the operation of the shutter unit 110a, the first and second irradiation times shown in FIG. 9A can be realized.

Note that the installation position of the shutter unit 110a is not limited to the optical path from the LED 1a to the valuable medium 100. Specifically, as shown by the broken line in FIG. 10A, the shutter unit 110b may be installed on the optical path where the light excited by the valuable medium 100 reaches the light emission measurement sensor 2b. . If the passage and blocking of the light excited by the valuable medium 100 is controlled, the same measurement result as that obtained when the irradiation time is controlled as shown in FIG. 9A can be obtained.

In addition, when the shutter unit 111 has a function of controlling not only the passage and blocking of light but also the amount of transmitted light, the shutter unit 111 is installed as shown in FIG. The emission intensity and the irradiation time of the excitation light irradiated to the valuable medium 100 from the LED 1a may be controlled. The timing control unit 12 controls the shutter unit 111 via the shutter control unit 122 in a state where the LED 1 a is always lit with the same light emission intensity by the light source control unit 11. Then, if the transmitted light amount of the excitation light from the LED 1a to the valuable medium 100 is controlled by the shutter unit 111, the first and second emission intensity and irradiation time shown in FIG. 9A can be realized. 10 (a) and 10 (b) show the luminescence measurement filter 4. If the luminescence measurement sensor 2b has characteristics that do not have light reception sensitivity in the excitation light band, measurement is performed. The configuration may be such that the filter 4 is omitted.

As described above, according to the present embodiment, the valuable medium 100 on which fluorescence emission or phosphorescence emission is observed by irradiating excitation light is different in emission intensity and irradiation time but with the same emission amount. By performing a plurality of set excitation light irradiations and measuring and comparing the light emission amounts of the light emission excited by each irradiation, it is possible to determine whether the light emission is fluorescent light emission or phosphorescence light emission. .

In addition, the difference in the amount of luminescence excited by the valuable medium at each irradiation can identify not only the difference between fluorescence and phosphorescence but also the type of phosphorescence. Even when different phosphorescence emission is detected in the valuable medium, the authenticity of the valuable medium can be determined based on the difference in the type of phosphorescent emission between the true valuable medium and the false valuable medium.

Further, the authenticity determination of the valuable medium 100 can be performed with higher accuracy by taking into account the position information on the valuable medium 100 that has been excited by fluorescence and phosphorescence by irradiating the excitation light.

As described above, the present invention is a technique useful for distinguishing and detecting fluorescence emission and phosphorescence emission observed on a valuable medium, and determining the authenticity of a valuable medium using the detection result of fluorescence and phosphorescence. This technique is useful when

1 Light source 1a LED
DESCRIPTION OF SYMBOLS 1b Light source monitor sensor 2 Light receiving part 2a Condensing lens 2b Light emission measurement sensor 3 Light source filter 4 Measurement filter 5 Substrate 6a Opening window part 6b Partition plate 10 Fluorescence / phosphorescence detection device 11 Light source control part 12 Timing control part 13 Light

emission Determination unit

14, 15 Integrator 30 Authenticity determination unit 100 Valuable medium 110a, 110b, 111 Shutter unit 121, 122 Shutter control unit

Claims

A fluorescence / phosphorescence detection method for detecting fluorescence emission and phosphorescence emission with different time characteristics of emission intensity when irradiated with the same excitation light,
A first excitation light irradiation step of irradiating the valuable medium with excitation light for a first irradiation time at a first emission intensity;
A first light emission amount measuring step of measuring a light emission amount from the valuable medium excited by the excitation light irradiated in the first excitation light irradiation step;
During the second irradiation time that is different from the length of the first irradiation time, the valuable medium is applied with the second light emission intensity that is set to be the same light amount as the excitation light irradiated in the first excitation light irradiation step. A second excitation light irradiation step of irradiating the excitation light toward,
A second light emission amount measuring step of measuring a light emission amount from the valuable medium excited by the excitation light irradiated in the second excitation light irradiation step;
By comparing the measurement result obtained in the first light emission amount measurement step with the measurement result obtained in the second light emission amount measurement step, it is determined whether the light emission from the valuable medium is fluorescence emission or phosphorescence emission. A fluorescence / phosphorescence detection method comprising: a light emission determination step for determining.
In the light emission determination step,
When the first emission amount measured in the first emission amount measurement step and the second emission amount measured in the second emission amount measurement step are the same, the emission from the valuable medium is fluorescence emission. Judge that there is
2. The fluorescence / phosphorescence detection method according to claim 1, wherein when the first emission amount and the second emission amount are different, the emission from the valuable medium is determined to be phosphorescence emission.
In the light emission determination step, when the first light emission amount and the second light emission amount are different, the first light emission amount and the second light emission amount are compared to identify the type of phosphorescent light emission. The fluorescence / phosphorescence detection method according to claim 1 or 2.
A fluorescence / phosphorescence detection device that detects fluorescence emission and phosphorescence emission with different time characteristics of emission intensity when irradiated with the same excitation light,
A light source that emits excitation light toward a valuable medium;
The first irradiation time is irradiated with the excitation light at the first emission intensity, and the irradiation is performed at the first irradiation time and the first emission intensity during the second irradiation time that is different from the time length of the first irradiation time. A light source control unit that controls the light source so as to irradiate excitation light at a second emission intensity set to have the same light amount as excitation
A sensor for measuring luminescence excited by the valuable medium;
The first emission intensity obtained by measuring the emission emitted by the first emission intensity and the excitation light of the first irradiation time by the sensor, and the excitation light of the second emission intensity and the second irradiation time. A light emission determination unit that compares the second light emission amount obtained by measuring the excited light emission with the sensor and determines whether the light emission from the valuable medium is fluorescent light emission or phosphorescent light emission; Fluorescence / phosphorescence detection device characterized by that.
The light emission determination unit
When the first light emission amount and the second light emission amount are the same, it is determined that the light emission from the valuable medium is fluorescent light emission,
5. The fluorescence / phosphorescence detection device according to claim 4, wherein when the first light emission amount and the second light emission amount are different, the light emission from the valuable medium is determined to be phosphorescent light emission.
The light emission determination unit identifies the type of phosphorescence emission by comparing the first light emission amount and the second light emission amount when the first light emission amount and the second light emission amount are different from each other. The fluorescence / phosphorescence detection device according to claim 4 or 5.
A light source filter that transmits the excitation light from the light source side to the valuable medium side and blocks light emission from the valuable medium side to the light source side;
A light source monitor sensor provided in the vicinity of the light source on the light source side in order to monitor irradiation of excitation light from the light source;
A timing control unit that determines a control timing of the light source based on an output from the light source monitor sensor;
The fluorescence / phosphorescence detection apparatus according to claim 4, wherein the light source control unit is controlled by the timing control unit.
A method for determining the authenticity of a valuable medium by detecting fluorescence emission and phosphorescence emission having different time characteristics of emission intensity when irradiated with the same excitation light and determining the authenticity of the valuable medium based on the detection result,
A first excitation light irradiation step of irradiating the valuable medium with excitation light for a first irradiation time at a first emission intensity;
A first light emission measurement step of measuring a light emission amount from the valuable medium excited by the excitation light irradiated in the first excitation light irradiation step;
During the second irradiation time that is different from the length of the first irradiation time, the valuable medium is applied with the second light emission intensity that is set to be the same light amount as the excitation light irradiated in the first excitation light irradiation step. A second excitation light irradiation step of irradiating the excitation light toward,
A second emission measurement step of measuring the amount of light emitted from the valuable medium excited by the excitation light irradiated in the second excitation light irradiation step;
By comparing the measurement result obtained in the first luminescence measurement step with the measurement result obtained in the second luminescence measurement step, it is determined whether the luminescence from the valuable medium is fluorescence emission or phosphorescence emission. A fluorescence / phosphorescence determination step,
A method for determining authenticity of a valuable medium, comprising: a true / false determination step for determining the authenticity of the valuable medium based on a determination result in the fluorescence / phosphorescence determination step.
A valuable medium authenticity determination device that detects fluorescence emission and phosphorescence emission with different time characteristics of emission intensity when irradiated with the same excitation light and determines the authenticity of the valuable medium based on the detection result,
A light source that emits excitation light toward a valuable medium;
The first irradiation time is irradiated with the excitation light at the first emission intensity, and the irradiation is performed at the first irradiation time and the first emission intensity during the second irradiation time that is different from the time length of the first irradiation time. A light source control unit that controls the light source so as to irradiate excitation light with a second light emission intensity set to have the same light amount as excitation
A sensor for measuring luminescence excited by the valuable medium;
Excited by the light emission amount obtained by measuring the light emission excited by the first emission intensity and the excitation light of the first irradiation time by the sensor, and the excitation light of the second emission intensity and the second irradiation time. A light emission determination unit that compares the light emission obtained by measuring the emitted light with the sensor and determines whether the light emission from the valuable medium is fluorescent light emission or phosphorescent light emission;
An authenticity determination device for a valuable medium, comprising: a true / false determination unit that determines the authenticity of the valuable medium based on a determination result by the light emission determination unit.